I. Field
The present disclosure relates generally to communication, and more specifically to techniques for paging terminals in a wireless communication system.
II. Background
A terminal in a wireless communication system (e.g., a cellular phone in a cellular system) may operate in one of several states, such as active and sleep states, at any given moment. In the active state, the terminal may actively exchange data with one or more base stations, e.g., for a voice or data call. In the sleep state, the terminal may be powered down much of the time to conserve battery power and may periodically monitor a paging channel for paging messages sent to the terminal. These paging messages may alert the terminal to the presence of an incoming call or provide other information.
The terminal may be portable and powered by an internal battery. In this case, it is desirable to reduce power consumption while in the sleep state in order to extend both standby time between battery recharges and talk time when a call is made. Lower power consumption may be achieved by sending paging messages in designated paging intervals that are spaced far apart in time, which then allows the terminal to power down for a large percentage of the time. However, sending paging messages at an infrequent rate may result in a long response time to page the terminal. For example, if an incoming call is received right after one paging interval, then the system would need to wait until the next paging interval, which may be far away, before the system can page the terminal. This long paging response may be undesirable or unacceptable for some applications requiring fast response time, such as push-to-talk, instant messaging, and so on.
There is therefore a need in the art for paging techniques that can achieve both fast paging response and low power consumption for terminals.